蒌蒿(Artemisia selengensis)对土壤中镉的胁迫反应及修复潜力研究

以洞庭湖湿地新发现的Cd高富集植物——蒌蒿(Artemisia selengensis)为试验材料,采用盆栽方式,系统研究了蒌蒿在生长期内对Cd的性状反应及富集特征.结果表明,大于40mg.kg-1的Cd胁迫对蒌蒿叶片伤害明显,且导致生物量下降,但植株在100mg.kg-1胁迫下可完成生活史,对Cd有较强的耐受能力;土壤中有效态Cd的含量仅占土壤全Cd含量的15.3%～37.1%;相同胁迫浓度下,各生长阶段的植株体内Cd含量差别不大,但由于生物量的原因,幼苗期对Cd的提取量显著小于其他时期,其中40～60mg.kg-1的Cd处理可使蒌蒿地上部分Cd含量达492～588mg.kg-1(成株期),且植株对该浓度范围的Cd污染去除效果最好;蒌蒿可作为对湿地土壤Cd污染较理想的修复植物加以研究和利用.     

Association of hearing loss with total and cause-specific mortality in US adults

Environmental Science and Pollution Research - We expected to explore the associations of hearing loss and hearing thresholds at different frequencies with total and cause-specific mortality. In...     

Biogeochemical zonation of sulfur during the discharge of groundwater to lake in desert plateau (Dakebo Lake,NW China)

As one of the important elements of controlling the redox system within the hyporheic and hypolentic zone, sulfur is involved in a series of complex biogeochemical processes such as carbon cycle, water acidification, formation of iron and manganese minerals, redox processes of trace metal elements and a series of important ecological processes. Previous studies on biogeochemistry of the hyporheic and hypolentic zones mostly concentrated on nutrients of nitrogen and phosphorus, heavy metals and other pollutants. Systematic study of biogeochemical behavior of sulfur and its main controlling factors within the lake hypolentic zone is very urgent and important. In this paper, a typical desert plateau lake, Dakebo Lake in northwestern China, was taken for example within which redox zonation and biogeochemical characteristics of sulfur affected by hydrodynamic conditions were studied based on not only traditional hydrochemical analysis, but also environmental isotope evidence. In the lake hypolentic zone of the study area, due to the different hydrodynamic conditions, vertical profile of sulfur species and environmental parameters differ at the two sites of the lake (western side and center). Reduction of sulfate, deposition and oxidation of sulfide, dissolution and precipitation of sulfur-bearing minerals occurred are responded well to Eh, dissolved oxygen, pH, organic carbon and microorganism according to which the lake hypolentic zone can be divided into reduced zone containing H₂S, reduced zone containing no H₂S, transition zone and oxidized zone. The results of this study provide valuable insights for understanding sulfur conversion processes and sulfur biogeochemical zonation within a lake hypolentic zone in an extreme plateau arid environment and for protecting the lake–wetland ecosystem in arid and semiarid regions.     

撬装式含油污水处理装置的研制

介绍了撬装式含油污水处理装置的研制过程.通过对液-液水力旋流技术、聚结斜板沉降技术、多滤料过滤技术等方面的研究,研制出一套撬装式含油污水处理装置,该装置具有结构紧凑、处理效果好、占地面积小、便于操作、便于运输的特点,适于小区块或边缘油田含油污水的处理.经现场实验,当停留时间仅为5 s时,即可获得较高的除油效率,在进口含油小于150 mg/L时,可将出口水中含油控制在30 mg/L以下,在进口悬浮固体含量小于100 mg/L时,可将出口水中悬浮固体含量控制在20 mg/L以下,使出口水质达到了行业标准SY/T5329-94中的中渗透率油田的B1级的注水标准,实现了含油污水处理后的就地回注,大大节省了污水处理成本.     

紫外辐射增强对麦二叉蚜发生量的影响

研究春小麦大田栽培自然光条件下,模拟紫外辐射（ＵＶ－Ｂ,２９０￣３１５ｎｍ）分别增加２．５４、４．２５及５．３１ｋＪ·ｍ＾－２对小麦（寄生虫麦二叉蚜（Ｓｃｈｉｚａｐｈｉｓ ｇｒａｍｉｎｕｍ）的发生、种群密度、繁殖系数等方面的影响。结果表明麦二叉蚜的种群密度与其当年的发生量密切相关,并且种群密度随着ＵＶ－Ｂ辐射强度的增加明显降低,但对麦二叉蚜的繁殖特性没有显著的抑制作用。因此认为,未来臭氧层减薄紫外